This invention relates to spring fasteners, and more particularly to those fasteners which are suitable to be engaged in a slot of a solid sheet and support the extension of a panel in a manner that one side of the solid sheet is sealed from the other side around the slot.
A number of fasteners have been used in the past for securing one object on another object, as for example, securing an article such as for example a plastic sheet on a metal or other rigid plastic sheet. However, the fasteners being used presently are particularly designed for only a limited number of matching objects to be secured on each other. For sealing purposes, a secondary resilient sheet, or a resilient body attached to the fastener may be used.
Examples of conventional fasteners are disclosed in U.S. Pat. No. 5,987,714 (Smith); U.S. Pat. No. 5,887,319 (Smith); U.S. Pat. No. 5,542,158 (Gronau et al.); U.S. Pat. No. 5,422,789 (Fisher et al.), U.S. Pat. No. 5,373,611 (Murata); U.S. Pat. No. 5,314,280 (Gagliardi); U.S. Pat. No. 5,095,592 (Doerfling); U.S. Pat. No. 4,792,475 (Bien); U.S. Pat. No. 4,683,622 (Ohelke); U.S. Pat. No. 4,609,170 (Schnabl); U.S. Pat. No. 4,245,652 (Kelly et al.); U.S. Pat. No. 3,864,789 (Leitner); U.S. Pat. No. 3,673,643 (Kindell); U.S. Pat. No. 3,525,129 (Holton); U.S. Pat. No. 2,825,948 (Parkin); U.S. Pat. No. 2,607,971 (Bedford, Jr.); U.S. Pat. No. 2,542,883 (Tinnerman); U.S. Pat. No. 2,329,688 (Bedford, Jr.); U.S. Pat. No. 2,322,656 (Murphy), among others.
U.S. Pat. No. 5,887,319; U.S. Pat. No. 5,987,714; patent application Ser. No. 09/493,476, filed Jan. 28, 2000; patent application Ser. No. 09/494,112, filed Jan. 28, 2000;and patent application Ser. No. 09/493,304, filed Jan. 28, 2000; describe fasteners suitable to be used in a slot, and they are all incorporated herein by reference.
As aforementioned, this invention relates to spring fasteners characterized by a structure suitable to be engaged in a slot. More particularly, this invention pertains a sealing spring fastener comprising:
a U-shaped structure having a first side, a second side, a top end and a bottom end;
a spring leg on each side of the U-shaped structure, extending outwardly from said U-shaped structure in a general direction from the bottom end toward the top end, each spring leg having an attached end and a free end; and
an elastic body integrally molded on the U-shaped structure at least with the top end, except at least the free end of each extending leg, the elastic body having a closed cavity within the first side and the second side of said U-shaped structure.
It is important that the elastic body comprises an underseal extending under each spring leg. In other words, the underseal is an extension of the elastic body.
The elastic body further comprises a gasket extending away from the closed cavity in the vicinity of the top end. It is also important that the gasket comprises at least one sealing rim, thus improving considerably the sealing properties of the gasket.
The elastic body preferably comprises a compound selected from a group consisting of thermoplastic elastomer, silicone, polyurethane, plastisol, and a mixture thereof. More preferably, the elastic body comprises a thermoplastic elastomer, and even more preferably the elastic body has been molded by insert injection molding.
The free end of each leg is engageable with a slot of a solid sheet. The gasket seals the top of the slot upon engagement of the free end of each slot with the slot of said solid sheet.
The sealing fastener of the present invention preferably further comprises barbs inside the closed cavity having a general direction from the top end toward the bottom end of the U-shaped structure.
The present invention also pertains a vehicle comprising two parts connected with a sealing spring fastener, the sealing fastener comprising:
a U-shaped structure having a first side, a second side, a top end, a bottom end, an upper section, and a lower section;
a spring leg on each side of the U-shaped structure, extending outwardly from said U-shaped structure in a general direction from the bottom end toward the top end, each spring leg having an attached end and a free end;
a casing surrounding at least partially the lower section of the U-shaped structure, except at least the free end of each extending leg, the casing enclosing a cavity within the first side and the second side of said U-shaped structure, the casing having an upper sector and a lower sector; and
an elastic body comprised of at least a gasket, the gasket extending away from the closed cavity in the vicinity of the top of the U-shaped structure, the gasket having an upper side and a lower side;
wherein the casing has lower ultimate elongation, higher Shore hardness, and higher shear strength than the elastic body.
Preferably, the casing has lower ultimate elongation, higher Shore hardness, and higher shear strength than the elastic body. Even more preferably, the casing is substantially non-elastic. Preferably, the cavity is formed at least partially by a portion of the elastic body, said portion of the elastic body being at least partially surrounded by the casing.
The casing may comprise a lip at the upper sector of the casing, the lip being embedded between the upper side and the lower side of the gasket, and the lower sector of the casing may comprise emerging sides. Further, the casing is suitable to be attached or bonded to the elastic body.
The casing may preferably comprise a plastic material which is substantially non-elastic at room temperature, and preferably the elastic body comprises a compound selected from a group consisting of thermoplastic elastomer, silicone, polyurethane, plastisol, and a mixture thereof. Nylon 6,6, preferably containing lubricant, is preferred as the molding material for the casing, while thermoplastic elastomers are preferred as the elastic body.
As also mentioned above, the sealing fastener may further comprise barbs inside the closed cavity having a general direction from the top end toward the bottom end of the U-shaped structure. Further, the barbs are preferably bent for stronger holding or exertion force, as described and claimed in provisional application 60/118,046 filed Feb. 1, 1999 and patent application Ser. No. 09/482,714, filed Jan. 13, 2000, both of which are incorporated herein by reference.
Further, this invention is related to a method of making the sealing spring fasteners described above. This method comprises steps of.
(a) forming the U-shaped structure;
(b) forming the casing;
(c) inserting the U-shaped structure into an insert mold;
(d) inserting the casing over the U-shaped structure in the insert mold;
(e) molding the elastic body in said insert mold, thereby forming the sealing spring fastener.
The steps (c) and (d) may be replaced by steps:
(cxe2x80x2) making an assembly by inserting the U-shaped structure into the casing; and
(dxe2x80x2) inserting the assembly into the insert mold.
This invention also relates to an assembly of a panel having an extension and a sealing spring fastener, according to any of the variations described above, wherein the extension of the panel is inserted into the closed cavity.
This invention also relates to a vehicle comprising two objects connected with any of the fasteners in any of the variations described above.